Abstract Streptococcus agalactiae (group B Streptococcus, GBS) is a major pathogen in humans and animals. Pili and biofilm may be important virulence factors in this bacterial species. Here, biofilm production and the distribution of pilus variants among 134 GBS isolates from human and animal sources were evaluated. Biofilm production was significantly enhanced in 1% glucose-supplemented medium (p < 0.05). Using this medium, most GBS strains were strong biofilm producers. Biomass was mainly composed of proteins, followed by extracellular DNA, while polysaccharides represented a minor portion. All GBS strains presented at least one pilus variant. PI-2a was the most common among human GBS while PI-2b was the most common among animal isolates. Human GBS harboring PI-2b and animal GBS harboring PI-2a presented significantly reduced biofilm production (p = 0.0033). In conclusion, strong biofilm production seems to be a common characteristic in GBS, and association of the clinical source with the pilus variant may be crucial for this.

中文翻译：

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从人和动物来源分离的无乳链球菌中菌毛变体的生物膜产生和分布

摘要 无乳链球菌（B组链球菌，GBS）是人类和动物的主要病原体。菌毛和生物膜可能是该细菌物种的重要毒力因子。在这里，评估了来自人类和动物来源的 134 种 GBS 分离株中的生物膜产生和菌毛变体的分布。生物膜的产生在 1% 葡萄糖补充培养基中显着增强 (p < 0.05)。使用这种培养基，大多数 GBS 菌株是强大的生物膜生产者。生物质主要由蛋白质组成，其次是细胞外DNA，而多糖占一小部分。所有 GBS 菌株都呈现出至少一种菌毛变体。PI-2a 在人类 GBS 中最常见，而 PI-2b 在动物分离株中最常见。携带 PI-2b 的人类 GBS 和携带 PI-2a 的动物 GBS 表现出显着降低的生物膜产生（p = 0.0033）。总之，强烈的生物膜产生似乎是 GBS 的一个共同特征，临床来源与菌毛变异的关联可能对此至关重要。